1. Field of the Invention
The present invention generally relates to a liquid crystal display apparatus, and particularly to a liquid crystal display apparatus having an adjustable viewing angle.
2. Description of Related Art
A typical LCD apparatus includes a display module and a drive module. The drive module is used for processing data, and the display module is used for displaying images according to the data. A performance of the LCD apparatus depends on characteristics of the display module.
Referring to FIG. 3, a liquid crystal display apparatus includes a conventional display module 999. The display module 999 includes a backlight source 100 and an LCD panel 200. The backlight source 100 is used for emitting light. The LCD panel 200 is used for selectively transmitting the light to display images. The LCD panel 200 has various types, and one typical type is TFT (Thin Film Transistor) LCD panel. As a TFT LCD panel, the LCD panel 200 includes an array of display units 210.
Referring to FIG. 4, the display unit 210 includes a first polarizing plate 211, a second polarizing plate 212, a liquid crystal layer 213, and a color filter 214. The first polarizing plate 211 is used for converting the light to linearly polarized light. The liquid crystal layer 213 is used for transmitting the linearly polarized light. When a voltage is applied across the liquid crystal layer 213, the linearly polarized light passes through liquid crystal layer 213 normally. When no voltage is applied across the liquid crystal layer 213, a polarization of the linearly polarized light is rotated at 90 degrees. The second polarizing plate 212 is used for absorbing the linearly polarized light when no voltage is applied across the liquid crystal layer 213. The second polarizing plate 212 is also used for transmitting the linearly polarized light when the voltage is applied across the liquid crystal layer 213. The color filter 214 is used for modulating the linearly polarized light to make the displayed images more colorful.
The liquid crystal layer 213 accommodates liquid crystal molecules 217. The liquid crystal layer 213 includes a first transparent electrode 215, a second transparent electrode 216, a first alignment film 218, and a second alignment film 219. The first transparent electrode 215 and the second transparent electrode 216 are set on two sides of the liquid crystal layer 213 to generate an electric field therebetween. The first alignment film 218 is formed on an inner surface of the first transparent electrode 215 along a first direction, and the second alignment film 219 is formed on an inner surface of the second transparent electrode 216 along a second direction. The first direction is perpendicular to the second direction.
When no voltage is applied across the liquid crystal layer 213, the liquid crystal molecules 217 are forced into a 90-degree twisted structural arrangement between the first alignment film 218 and the second alignment film 219. According to characteristic of the liquid crystal molecules 217, a polarization of the linearly polarized light is rotated 90 degrees as the linearly polarized light passes through the liquid crystal layer 213. When the voltage is applied across the liquid crystal layer 213, the liquid crystal molecules 217 are aligned parallel to the electric field and the linearly polarized light passes through the liquid crystal layer 213 normally.
When the LCD apparatus is used, it is often needed to rotate the LCD apparatus to slant to users. However, when the LCD apparatus is placed in a corner of a room, the space of the corner restricts rotation of the LCD apparatus. That is, it is convenient to directly rotate the LCD apparatus in the corner and a large space is needed.
Therefore, an LCD apparatus is needed in the industry to address the aforementioned deficiencies and inadequacies.